47 2 
INDEX. 
Marsupialia, South American, 362 
Martesia, 10, 755 
argentinensis, 4, 27 
patagonica, 155, 156, 157, 257, 261, 267, 
272, 273, 277, 279, 282, 292, 295 
peroni, 156, 292 
pumila, 136, 257, 267 
Matthew, W. D., 334 
Mayer Basin, 49, 277, 285 
Medlicott, H. B., 61 
Meek, F. B., 14, 15 
Melicerita, 65, 66 
angustiloba, 66, 299, 301 
atlantica, 66 
charlesworthi, 66, 291 
dubia, 66 
triforis, 63, 257, 275, 291, 295, 299,301 
Mellita, 56 
Mercenaria cancellata, 138 
Mercerat, A., 287, 288, 444 
Meretrix, 142, 323 
alta, 304 
crassa, 304 
iheringi, 742, 257, 262, 268, 280 
pseudocrassa, 742, 256, 304 
rostrata, 143, 2 5 8, 307, 308 
Mesonychidae, 336, 337 
Mesonyx, 335, 350 
Mesozoic, 10, 15 
MetaepanortJms, 425, 426 . 
compile atus, 455 
holmbergi , 455 
intermedins , 430 
Metriodromus, 453 
arenarus, 453 
crassidens, 453 
crassus, 453 
spectans, 453 
Micraster atacamensis , 62, 63 
valdivianus , 62, 63 
Microbio th a idee, 339, 408 
Microbiotherium, 335, 339, 395, 397, 4 q8, 
450 
conspicuum, 450 
forticulum, 450 
gallegosense, 41 1, 413 , 414 
Microbiotherium patagonicum, 409, 413 
sp., *409 
tehuelchum, 409, 410, 41 1, 413, 414 
tortor, 408, 409, 41 1, 412, 414 
Milne-Edwards, A., 256 
Miocene, 34, 287, 288, 295, 296, 297, 299, 
300, 302, 306, 340 
Lower, 288, 297, 299, 303 
Mitra, 322 
Modiola, 121 
ameghinoi, 121, 257, 262, 273, 283,460 
andina, 722, 257, 278, 279, 281 
coquimbana, 122 
laeviuscula, 122 
rugulosa, 122 
Moericke, W., 79, 101, 105,110, 112, 120, 
146, 189, 193, 194, 198, 212, 223, 224, 
244, 246, 250, 254, 290, 298, 299, 308 
Mollusca, Tertiary, So, 444 
Monophora, 57, 58 
darwini, 57, 76 
Monotremata, 336, 338 
Moreno, F. P., 416 
Morgan, J. P., 207 
Mt. Leon, 26S 
of Observation, 48, 272, 273 
Multituberculata, 443, 444 
Murex, 2/4, 322 
hatcheri, 214, 220, 258, 274, 294, 296 
Muricidae, 214 
Murray, J., 319 
Museum, American, of Nat. Hist., 334, 37 2, 
387, 401, 41 1, 415, 4 2 r > 425, 428, 
430, 432, 436, 437, 444 
British, 334 
La Plata, 408, 410 
Mytilidae, 120 
Mytilus, 120 
argentinus, 4, 5, 16 
chorus, 720, 257, 258, 262, 266, 275, 
282, 289, 298, 307, 308, 323 
cuvieri, 8 
magellanicus, 121, 257, 274, 289, 299, 
323 
sp., 277 
ungulatus , 120 
